Electrical connectors are extremely diverse in type and number. However, standardization within certain industries such as, for example, the communications and computer industries has driven manufacturers to adopt the use of standard connectors in many applications. Interoperability between products made by a diversity of manufacturers within these and other industries is so important, particularly for network and telephone interfaces, that the use of proprietary or non-standard connectors for standard communications interfaces could likely compromise the marketability of products containing them and would be largely unthinkable.
As the computer and communications worlds have converged, the demand for interconnection between computers and, for example, the public phone system have driven computer makers to use standard connectors to facilitate such interconnection and the rich content available therefrom. Such standard connectors are also rugged, multi-sourced, reliable, and inexpensive. The RJ-series connector, such as the RJ-11 and RJ-45 connectors, represents such a standard connector. RJ stands for “Registered Jack” and is specified according to the standards called out in U.S. Federal Communications Commission rules and regulations, 47 C.F.R. 68. The RJ series connectors were originally developed by AT&T as a modular connection solution for telephone handsets and wall plugs and are now used by almost all telephone companies throughout the world. The RJ connectors are configured based on a connection form factor and an actual number of connections. For example, the RJ-11 and RJ-12 are the same size, e.g. A six connection form factor, with the RJ-11 having four connections and the RJ-12 having six connections. The connection protocol is typically center oriented so that modifications can be made without disturbing existing service. Although now used for many different applications, the most important use for the RJ series connectors, particularly the RJ-11 connector, is the interconnection of telephones, modems, and computers with telephone lines. Accordingly, stringent standardization of connectors has been established to enable compatibility and interoperability. Due to the simplicity of the connector design, the reliability of the connections, and the fact that the connectors are manufactured under established standards, RJ-series connectors are used extensively in the computer industries and in other industries where communication over telephone lines or standard interconnection is required.
The standard RJ-series modular connector includes a plug or contact block and a jack or socket having a certain number of mating contacts. The plug includes a small block shaped body typically having pressure activated blades which can be crimped on to a cable, such as a telephone line typically having individual conductors. The crimping action provides a connection between the individual conductors and the contact surface of the blade which is then positioned to contact a corresponding spring contact generally housed within the jack or socket. The outside of the body is molded with a flexible retention clip or key that allows the plug to be secured within the socket. A portion of the clip extends outside the plug/jack mating area to allow the plug to be easily disconnected by depressing the clip and pulling the plug.
The socket can be integrated into a circuit board and can be accessed through a port in the housing or enclosure of associated equipment or can be molded directly into an enclosure and wired to a circuit board. The socket may be mechanically configured to receive the plug and contains flexible contact wires aligned with and biased against corresponding contacts on the plug to complete the electrical connection between the plug and the electrical apparatus.
The interior surface of the socket includes a receiving notch for accepting the retention clip of the plug so as to mechanically secure the plug within the socket. Once the retention clip has snapped into place within the receiving notch through a flexing action of the retention clip away from the body of the plug, the plug is firmly held in place providing secure mechanical and electrical coupling. To remove the plug, the retention clip is manually flexed back towards the body of the plug to release the retention clip from the notch, enabling manual removal of the plug from the socket. While the basic characteristics and operation of the RJ-11 plug has been described herein, other RJ series plug and jacks are used extensively in electronic, computer, and communications devices and operate in the same basic manner.
The RJ-45 modular connector, for example, is used extensively for network interface interconnections and possesses many of the same basic characteristics of the RJ-11 plug described previously herein. The RJ-45 connector has a larger width dimension than the RJ-11 and is configured to facilitate eight connections. The RJ-11 is configured for four connections but has a form factor to accommodate six. It is important to note that perhaps due to legacy compatibility concerns, e.g. concerns that later versions of RJ designs would accept earlier designs, the RJ-45 connector although wider can accommodate an RJ-11 connector.
Problems arise however since although the RJ-11 plug may be plugged into an RJ-45 jack, the wiring of the RJ-45 may deviate from normal telephone connection protocol as it typically does for network connectivity commonly associated with modem applications of the RJ-45 form factor. Thus damage due to improper electrical connection is possible. And further, although detection of a properly inserted plug is relatively easy, the detection of an improperly inserted plug is not easily addressed as evidenced by the lack of adequate solutions in the art.
Some plugs have been configured to detect the presence of a jack therewithin as described for example in U.S. Pat. No. 5,378,165 issued on Jan. 3, 1995 to Comerci et al (hereinafter “Comerci”). The plug described in Comerci however is configured to detect a properly inserted plug and fails to teach or suggest how to deal with an improperly inserted plug. Comerci further appears to require that the plug be fully inserted before detection can occur. Still further, Comerci requires separate assemblies for the plug housing and detection means leading to increased cost of manufacture and assembly. In U.S. Pat. No. 5,772,466 issued on Jun. 30 1998 to Morin et al. (hereinafter “Morin”), a receptacle connector adapted for mating with at least two types of plug connectors is described. Morin's receptacle generates a signal when mating with one type connector and does not generate a signal when mating with the other type of connector. The obvious problem with Morin's approach is that there is no way to distinguish whether the lack of a signal indicates that an improper plug type is plugged into the receptacle or whether the receptacle is simply empty.
Thus, it would be desirable in the art for a solution to the abovementioned problems by providing for detection of an improperly inserted plug into a receptacle which can physically accommodate more than one plug type. In addition to detecting the improperly inserted plug it would be further desirable for the detection of a properly inserted plug.